Before the cold weather blows in and the winter fruit tree sales start up, I want to take this opportunity to warn people about some of the common pitfalls associated with buying citrus trees. Citrus trees generally don't grow well on their own roots, and so they are usually grafted onto rootstocks. However, not all rootstocks grow well in Houston's climate and soils, so selecting citrus trees grafted onto the appropriate rootstocks is critical if you want your new citrus tree to grow and thrive.Poncirus trofoliata (Trifoliate) is generally considered to be the best rootstock for Houston, but it can also be the hardest to find. Many growers choose to use other rootstocks other than Trifoliate because they produce trees large enough for sale more quickly than the slower-growing Trifoliate. I prefer to buy trees grafted onto Trifoliate and Flying Dragon (another type of Trifoliate), but I will also buy trees on Carrizo Citrange for well drained areas. I should also mention that I protect my citrus from hard freezes, and if you don't want to go through that effort, Carrizo Citrange isn't for you. Trees grafted onto other rootstocks such as Sour Orange, Volkamer Lemon, or Swingle Citrumelo either get sick in our clay soil, are killed by freezes, or are susceptible to pests/diseases, and I wouldn’t recommending them. Here are some brief descriptions of the various rootstocks commonly used by Houston area growers:

Trifoliate (PT, TF) - The most cold tolerant rootstock available; very resistant to root rot; grows well with poor drainage and clay soil; tough and resistant to many soil diseases; produces a semi-dwarf tree. Considered to be thebest all-around rootstock for Houston.

Flying Dragon (FD) - A more dwarfing form of trifoliate with curved thorns and branches; produces a very slow-growing dwarf tree. Good for tight spaces, or for trees that will be grown in containers.

Carrizo Citrange - A Trifoliate x Washington navel orange hybrid; cold tolerant, but vulnerable to rapid cold fronts and late freezes; sensitive to poor drainage. Good for trees that will be protected from hard freezes and planted in a slightly raised spot with better drainage.

Swingle Citrumelo (SW) - A Duncan grapefruit x Trifoliate hybrid; resistant to root rot, but it gets sick in heavy clay soil; relatively cold tolerant; produces a very vigorous tree. Only recommended for trees that will be protected from hard freezes and planted in very well-drained soil.

Sour Orange - The standard rootstock used in the Rio Grande Valley because it is tolerant of salty soils; moderately cold tolerant; produces a very vigorous tree. Not recommended for Houston.

Unfortunately, when shopping for a citrus tree at a nursery or a fruit tree sale, it can be very difficult to find out what rootstock a tree is grafted on. Most growers don’t list the rootstock on the label, most nursery employees won’t have any idea if you ask, and don't even bother asking at Home Depot or Walmart. Fortunately, there is a way to find out. By law, all citrus trees must carry a label that says “Produced in Texas”, and that lists the name and license number of the nursery where the tree was grown.Most often the only way to find out what rootstock was used is to contact the grower listed on the label. To try to make this easier for people, I called several growers that supply citrus trees to Houston area retail nurseries, and asked them what rootstock they used. The results of this survey are listed below, and have also been provided as a downloadable PDF. I highly recommend that you print out this list and take it with you when shopping for citrus trees, and use it make sure you're getting a good tree that will produce fruit for years.

Good info. My saxon becnel grown blood orange has been geting yellow quite a bit this year and i had wondering about the rootstock, since the wild trifoliates in the area are doing so well. I think i will raise it up this weekend to get it some more drainage.

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Jay

10/12/2012 09:36:04 am

You have no idea how much I love you for this list. Thank you so much!

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jclaytonbell

10/12/2012 11:21:06 am

Does it have lots of fruit on it? If so, it may be due to a magnesium deficiency

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Jay

10/16/2012 11:40:25 am

Okay, I've come to the conclusion that this list basically means you're not going to find any on-sale trees on trifoliate rootstock unless you head down to see Mr. Panzarella. Sigh, so much for fall planting.

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Clayton

10/22/2012 01:20:56 am

No true. You can get trees grafted onto triflolate from the Arbor Gate in Tomball, TX, or from Glen Miracle.

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Jim Hu

12/11/2012 06:18:49 pm

Appreciate your kindness for sharing your knowledge,
I love you

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Larry Tischler

1/17/2014 10:24:56 pm

I am an amateur citrus grower and have 32 citrus trees in the ground in Angleton. As a geologist, you know that the soil in the Greater
Houston area is quite variable. Many areas that have not been reworked
by recent streams have a lot of limey deposits in the subsoil. I have read these are the result of caliche formation during the ice age when the Gulf shoreline was out at the edge of the shelf. If one tries to grow citrus in
one of these places trifoliate rootstock is very problematical. It can be done, but you have to understand many pitfalls and work around them.
If not, the tree will not be healthy and will not be as cold hardy or productive as one on good soil. This was explained Dr. J. S. Nagle about 15 years ago.The second thing is the water can become very alkaline, about 8.2 pH. I have both these situations and have been trying the other rootstocks (except the lemons) with some success.

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Bonnie Childers

5/20/2016 07:54:48 pm

Clayton, I have not heard from you for quite some time. An aquaintace forwarded you web site.
Take Care,